I have one for about 2 years, but I just got two more, and they are very small! And it is a 55 gallon fish tank... I told my dad not to buy two because they get really big, but he did anyways! But My really big one that i've had for two years is about 9 inches...But he hasn't grown in forever! Is he, or my other two going to grow? And they also have worms that i can't get rid of! They have had them forever! But its not affecting them, and i've cleaned the fish tank out every week, but they still won't go away...What do I do??